In the medical field, surgical tools take many forms. In some cases, the tools are powered to perform surgical procedures. Such tools can include motorized surgical drills, burs, saws, reamers, and the like. The surgeon regulates a speed of the tool using a trigger member. Prior art methods for controlling the speed of the tool utilize a magnet and one or more Hall Effect sensors to measure a displacement of the trigger member. For example, Japanese patent JP 4879570B2 discloses a power tool with a magnet linked to a trigger member and two Hall Effect sensors to control a speed of the power tool.
Typically, tools used in surgical procedures are reusable, but need to be sterilized before each use. Some sterilization techniques can be harsh on components of the tool such as the magnet and/or the Hall Effect sensors. High temperatures involved in autoclave sterilization may cause degradation of such components. Such degradation may cause variations in the measurements of the displacement of the trigger member, potentially resulting in incorrect speeds of the tool, or the inability of the tool to reach a maximum speed. There remains an opportunity to address at least the aforementioned problems.